Buth, the former president of the Canola Council of Canada, was one of five senators Prime Minister Stephen Harper appointed in January 2012.
In a statement, Buth said joining the institute allows her to return to her roots.
"This opportunity represents coming home to me as I come back to work in an industry that is so critical to Canada and to Canada’s reputation internationally," she said in the statement Tuesday.
Fellow Manitoba Senator Don Plett posted a note on Buth's resignation on Twitter:
Also on HuffPost